At the end of the day, Nintendo executives would not have greenlit Labo if they didn't think it would be profitable (and beneficial to the brand in a significant way). So if they were anticipating low sales now, either it's already profitable or they're projecting much bigger sales down the road.
As I said before, comparing Labo sales trends to traditional video game titles doesn't make sense to me -- but I'd love to see a comparison between Labo sales and those of LEGO Mindstorms, because I think that's the closest analogy in the retail market (STEM edutainment at a premium price). That's another product that sits on store shelves 11 months out of the year and yet never gets price cuts. Unfortunately, I don't think we have any LEGO-sales-age members here, unless
MatPiscatella has hidden depths he hasn't shared with us before...